Bipolar disorder is a chronic and often disabling illness affecting 1-2% of US adults. Effective pharmacologic and psychosocial treatment can significantly reduce the burden of bipolar disorder, but current management falls far short of optimal. Peer support programs are an innovative and promising model to reverse consumer demoralization, activate consumers to seek more effective care, develop consumers' self-management skills, and restore participation in work and other social roles. Peer-led programs can address some key barriers to dissemination of effective psychosocial treatments including limited supply of trained providers, limited resources for new programs, and limited consumer demand for traditional services. We propose a pilot effectiveness trial evaluating the feasibility, acceptability, and effectiveness of a structured peer support intervention based on the Certified Peer Specialist Program of the Depression and Bipolar Support Alliance (DBSA). The intervention is based in the philosophy of recovery, and focuses on: fostering community and social support, motivating consumers to develop an expectation of recovery, activating consumers to be informed and effective self-advocates, training consumers to develop self-management skills for symptom control and problem solving, motivating and assisting consumers to reclaim work and other rewarding social roles. Consistent with the recovery model, impact of the intervention will judged across a range of outcomes: Long term control of mood disorder symptoms, optimal participation in work and other social roles, and consumers' perceptions of full participation in the treatment process. Specific aims of this pilot work include: 1) develop a model for structured peer support suitable for a range of health care settings, 2) conduct a pilot randomized trial comparing usual care plus peer support to usual care alone, and 3) refine the intervention and plan for a multi-site effectiveness trial.